Raisbeck Engineering says the next Learjet model likely to be considered for its ZR Technology performance-enhancement package after launch on the 35/36-series is the 31, followed by the 55 and 60. The Seattle-based company has begun certification flight testing of the initial Learjet 35ZR after unveiling the aircraft at the National Business Aviation Association annual convention, and expects supplemental type certification in the first quarter of 2004, with installations beginning in the second quarter.
The ZR modification reduces high-speed cruise drag by 10% and includes wing leading-edge gloves, reprofiled trailing-edge flaps and "horizontal winglets". The 45˚-swept gloves and reflexed flaps slow the supersonic airflow between wing and nacelles, while the "batwing" winglets block formation of wingtip vortices.
The upgrade allows the turbofan-powered Learjet 35/36 to achieve the same Mach 0.81 cruise capability at 41,000ft (12,500m) as the original turbojet-powered 20-series aircraft. After certification, the company will sell the first five to 10 Learjet 35/36 modifications for around $200,000.
Source: Flight International
